#include<iostream> using namespace std; int main() { int n; cin>>n; int a[n],b[n],i,j,m; for(i=0;i<n;i++) {cin>>a[i]; cin>>b[i];} for(i=0;i<n;i++) {for(j=n-1;j>i;j--) {if(a[j]==a[i]) {b[i]=b[i]+b[j]; b[j]=0; a[j]=-1;} if(a[i]>a[j]) { m=a[i]; a[i]=a[j]; a[j]=m; m=b[i]; b[i]=b[j]; b[j]=m; } }} for(i=0;i<n;i++) {if(a[i]!=-1) { cout<<a[i]<<" "; cout<<b[i]<<"\n";}} }